The examination of specimens, such as metals, ceramics, composites, cements, laminates, plastics, electronic components and biomaterials may require a number of preparatory steps. For example, a specimen may need to be cut or sectioned to a specific size prior to mounting for examination.
Saws are known for carrying out the sectioning, e.g., cutting of samples. Saws can be free-standing types, such as that disclosed in Adair et al., US Publication No. 2015/0217472 or table-top types, such as that disclosed in, US Publication No. 2012/0100780, the disclosures of which is incorporated herein by reference in its entirety.
In a typical sample preparation saw, the specimen is secured in a vise or chuck. The chuck is secured in an assembly that can be moved toward and away from the blade to position the specimen for cutting. The assembly is positioned along a T-slot in the base of the saw and secured by fasteners, such as screws or bolts. To remove or reposition the specimen, bolts are removed from the chuck and an upper portion, such as a saddle is removed to reposition the specimen. The assembly is then repositioned in on the base of the saw. Tools, such as hex drivers are required to remove the assembly from the base and to remove and reposition the specimen in the chuck. Fasteners in the assembly are then tightened, again using tools to secure the assembly along the T-slot in the base. Removing and repositioning the specimen in the chuck is required so that the cut is made in the proper location on along the specimen.
In operation, the saw blade is then manually positioned to affect the cut. In some known saws, the blade is moved toward the specimen to perform the cut. The location of the blade relative to the specimen may have to be manually adjusted along one or more of the x-, y- and z-axes to properly position the blade to perform the cut. Some saws in corporate automated movement in one or two directions. Other saws have a table or mounting that moves in one direction. For purposes of the present disclosure, the x-axis is parallel to the axis on which the saw blade rotates, the y-axis is perpendicular to the x-axis and is movement toward and away from the saw blade cutting edge, and the z-axis is along a vertical direction, that is in an up and down motion, toward and away from the saw base. The three axes are perpendicular to one another and define a spatial movement.
A lubricant and rinse solution, which may be, for example, water, is sprayed onto the blade and specimen during cutting operations to cool the specimen and blade and to rinse away debris and swarf that is generated during the cutting operation. The rinse water is collected in a collection tank in the bottom of the saw base. The rinse fluid is then pumped out of the recirculation tank for processing and/or disposal.
In known saws, the collection tank includes a serpentine or maze-like set of walls to reduce turbulence in the rinse fluid so that the heavier materials settle out prior to the discharge pump inlet. While these walls prevent some of the debris from entering the pump, these unwanted materials can clog the pump inlet resulting in overflow of the tank and can possibly cause the pump to run dry. Moreover, if debris is drawn into the pump, it may damage the pump internals, such as the pump casing or pump impeller.
In addition, depending upon the type of blade used, the blade may have to be dressed during the cutting operation. Dressing a blade is the process of removing worn material from the blade so as to expose a fresh cutting surface or edge. In known saws, dressing is carried out by positioning a dressing stick, such as a silicon carbide block, in a holder and moving the dressing stick into contact with the cutting edge of the blade. In one known saw, the dressing stick is driven by a drive into contact with the edge of the saw blade. The dressing stick may be incrementally moved, along its length to expose fresh (uncut) areas of the dressing stick to the saw blade edge. Such a system in used in the IsoMet® 4000 and 5000 linear precision saws, commercially available from Buehler, an ITW company, of Lake Bluff, Ill. The dressing stick must be manually installed on and removed from the saw by removing fasteners securing the holder to the saw and reinstalling the fasteners, using tools, to reposition and/or replace the stick.
Known saws have control system that control one or more of the steps necessary to carry out cutting, dressing and the like throughout the cutting cycle. The control interfaces, however, can be non-intuitive and may require significant operator interface or manual operation. In addition, the human-machine interfaces of known saws do not lend itself to step-by-step set up and operation in an automatic mode.
Accordingly, there is a need for an improved bench-top sample preparation saw. Desirably, such a saw has automated 3-dimensional movement and adjustability along the x-, y- and z-axes. More desirably, such a saw has tool-less specimen clamping and positioning assemblies to facilitate readily positioning and securing a specimen in the saw. More desirably still, such a saw has a dressing system that moves a dressing wheel into contact with the blade and indexes the dressing element to expose a fresh surface of the dressing element to the blade. Still more desirably, such a saw has a recirculation tank and system that readily separates debris and swarf from the cooling/lubricating/rinse fluid. Such a saw additionally includes an improved user interface that facilitates set up and use of the saw with minimal operator interface requirements.